1. Technical Field
The present invention relates to a system that protects a vehicle occupant during a rollover crash. More specifically, the present invention is a new type of safety system that is designed to prevent the vehicle roof from collapsing onto the vehicle occupant during a rollover crash.
2. Description of Related Art
Rollover crashes or accidents are some of the most serious accidents involving automobiles. As its name implies, a rollover crash is one in which the vehicle literally rolls over-i.e., the vehicle becomes inverted (at least for a short period of time) such that the vehicle's tires are positioned above the vehicle roof. Rollover accidents are extremely dangerous for convertible vehicles as there is no structure that will protect the occupant from harmfully impacting the ground. In fact, occupants of a convertible vehicle involved in a rollover accident are often killed or seriously injured.
Rollover accidents are a serious concern for non-convertible vehicles as well in that such accidents can cause injury/death to vehicle occupants. Generally, the occupants of a vehicle having a roof will be injured or killed in a rollover due to (1) the vehicle roof being forced down onto the occupant (thereby causing head trauma, spinal trauma, etc.) and/or (2) the occupant's head or torso being ejected through an opening in the vehicle such that the body part contacts the ground. Given these problems, a vehicle with a roof is not necessarily safer than a convertible vehicle in a rollover crash.
Because of the significant dangers/risks associated with rollover conditions, significant research and development has been conducted into constructing safety systems that protect vehicle occupants in a rollover. Some of the currently known systems include seatbelt pretensioning systems and side curtain airbag systems. While these systems provide increased protection to the vehicle occupant, such systems generally rely on specific anchorage points within the vehicle that secure the seatbelt system in place and restrain the occupant during the rollover. However, as the roof and/or side structure of the vehicle is generally deformed during a rollover, these anchorage points may move and/or become inoperable, thereby diminishing the overall effectiveness and ability of these systems to adequately protect occupants during the crash.
Other systems designed for rollover protection include deployable members, such as deployable rollbars or other structures. These systems are designed typically to support the entire weight/impact of the vehicle during a rollover. Unfortunately, for many passenger vehicles such as SUVs, the inclusion of the rollbar makes the vehicle interior cumbersome and unappealing.
Likewise, many of the rollbars or other deployable members create additional problems in that they are rigid systems that do not allow the roof to deform as part of the rollover incident. As is known in the art, it is sometimes desirable to have all or a portion of the vehicle roof deform during the rollover in that this deformation will actually dissipate some of the energy of the crash. If the roof/vehicle structure is so rigid such that no deformation occurs, there is a risk that the energy/angular momentum of the rollover crash will not be rapidly dissipated, which in turn, increases the risk that the vehicle will roll multiple times during the incident. Obviously, the more times the vehicle rolls during the crash, the greater the likelihood that the occupant will be injured. Accordingly, any safety system that does not allow all or a portion of the roof/vehicle to deform and dissipate some of the crash energy will generally be disfavored.
Other options for rollover safety systems involving the “A-pillar” and the “B-pillar” of vehicles involve making the “A-pillar” and the “B-pillar” more resistance to buckling or deformation. However, the problem with this method is that such a system adds significant unwanted weight and bulk to the vehicle, which increases the vehicle centre of gravity and hence propensity to roll-over and may also reduce the driver's visibility. Consumers will simply not accept these changes, regardless of any added benefits that may result for these changes. Accordingly, such systems are not viable “solutions” to the problems associated with rollover crashes.
Based upon the foregoing, it is clear that many currently known safety systems designed to protect a vehicle occupant during a rollover accident are inadequate or undesirable. Accordingly, it would be an advancement in the art to provide a new type of safety system that would protect vehicle occupants during rollover conditions and would overcome one or more of the problems/limitations discussed above. Such a system is disclosed herein.